Benzoxazolyl-1 3 4-oxdiazole derivatives

ABSTRACT

NEW BENZOXAZOLYL-1,3,4,-OXDIAZOLE COMPOUNDS ARE PROVIDED WHICH MAY BE REPRESENTED BY THE FORMULA   A1-BENZOXAZOL-2,6-YLENE-1,3,4-OXADIAZOL-2,5-YLENE-   ((B)(M-1)-1,3,4-OXADIAZOL-2,5-YLENE-A2)(N-1)   WHEREIN A1 AND A2 ARE IDENTICAL AND EACH REPRESENTS PHENYL, DIPHENYLYL, NAPHTHYL, STYRYL, STILBENYL, BENZOXAZOLYPHENYL, 1,3,4 - OXIDAZOLYLPHENYL, 6 - BENZOXAZOLYL, THINYL, PYRIDYL, PHENYLTHIENYL, BENZOXAZOLYLTHIENYL, PHENYLBENZOXAZOLYL OR 1,3,4-OXIDAZOLYTHIENYL RESIDUE; B REPRESENTS 1,4-PHENYLENE, 2,5-FUROYLENE OR 2,5-THIENYLENE, AND M AND N EACH IS 1 OR 2. THE BENZOXAZOLYL-1,3,4OXDIAZOLE COMPOUNDS OF THIS INVENTION MAY BE FURTHER SUBSTITUTED BY NON-CHROMOPHORIC, MONOVALENT SUBSTITUTENTS. THE COMPOUNDS OF THE PRESENT INVENTION ARE ESPECIALLY VALUABLE AS OPTICAL BRIGHTNERS FOR ORGANIC MATERIALS.

United States Patent 3,644,345- BENZOX-AZOLYL-1,3,4 0XDIAZOLEDERIVATIVES Adolf Emil Siegrist, Basel, Peter Liechti, Binningen, ErwinMaeder, Aesch, and Leonardo Guglielmetti, Birsfelden,

Switzerland, ssignors to Ciba Limited, Basel, Switzerland N0 Drawing.Continuation-impart of application Ser. No.

798,258, Feb. 3, 1969, which is a continuation of application Ser. No.548,413, May 9, 1966. This application July1'8;'1969, Ser. No. 843,199

Claims priority, applicatgitzlzs/vzistzerland, May 10, 1965,

l 9 Int. Cl, C09d 23/16; C07d 85/48, 31/40 US. Cl. 260-,440 CA 13 ClaimsI ABSTRACT OF THE DISCLOSURE New ben zoitazolylfl,3,4-oi diazolecompounds are provided which may be represented by the formula wherein Aand A are identical and each represents phenyl, diphenylyl, naphthyl,styryl, stilbenyl, benzoxazolylphenyl, 1,3,4 --.oxdiazolylphenyl, 6benzoxazolyl, thienyl, pyridyl, 'pheiiylthienyl, benzoxazolylthienyl,phenylbenzoxazolyl or 1,3,4-0Xdiazolylthienyl residue; B represents1,4-phenylene, 2,5-furoylene or 2,5-thienylene, and m and n each is 1 or2. The benzoxazolyl-1,3,4- oxdiazole compounds of this invention may befurther substituted by 'non-chromophoric, monovalent substituents.

The compounds of the present invention are especially valuable asoptical brighteners for organic materials.

CROSS-REFERENCES TO RELATED APPLICATIONS where A' and Ag areidentical ordifferent phenyl, diphenylyl, naphthyl, styryl, stilbenyl,vbenzoxazolylphenyl, 1,3,4-oxdiazolylphenyl, -6. -.benz'okazolyl,thienyl, pyridyl, phenylthienyl, benzoxazolylthienyl, phenylbenzoxazolylor 1,3,4-oxdiazolylthienyl residues; B represents a divalent bridgemember from theseries 1,4-phenylene, 2,5-furoylene and 2,5-thienylene,and"m and n eachis 1 or 2, and

these benzoxazolyl-1,3,4-oxdiazole derivatives may be 3,544,345 IcePatented Feb. 22, 1972 further substituted by non-chromophoric,monovalent substituents. As derivatives containing non-chromophoric,monovalent substituents there are suitable for practical purposes aboveall those compounds of the above Formula 2 which contain in terminalaromatic ring systems up to two, and in phenylene nuclei one,substituent(s) such as halogen, alkyl, phenyl, carboxyl, sulpho,hydroxyl or amino groups, and their substitutive or functionalderivatives.

Within the scope of the Forumla 2 as defined above non-chromophoric,monovalent substituents in terminal aromatic ring systems or inphenylene nuclei are, apart from the substituent groups specificallymentioned there, also those that can be directly derived therefromsubstitutively or functionally, for example apart from alkyl groups alsohalogenalkyl, hydroxyalkyl, cyanoalkyl carboxyalkyl, phenylalkyl andsimilar groups; apart from phenyl groups also alkylphenyl,halogenophenyl, alkoxyphenyl, carboxypheny and similar groups; apartfrom carboxyl groups also carboxylic acid ester, amide, nitrile,hydrazide and similar groups; apart from sulpho groups also sulphonicacid ester or sulphonamide, alkylsulphone and arylsulphone groups, apartfrom hydroxyl groups also alkoxy, aralkoxy, phenoxy and hydroxyalkoxygroups, apart from free amino groups also alkylated, arylated andacylated amino groups, urethane and urea derivatives, triazinylderivatives and similar compounds, provided they are non-chromophoric.

The compounds of practical interest therefore can be defined by theformula wherein A represents a member selected from the group consistingof (a) phenyl, (b) 4-(2-oXdiazol-[l,3,4]yl) phenyl which is substitutedin position 5 of the oxadiazolyl residue with a member selected from thegroup consisting of phenyl, 2-thienyl, 2-(5-phenyl) thienyl and4-stilbenyl, (c) 2-(5-phenyl) thienyl, (d) 4-diphenylyl and (e) 4-stilbenyl, (f) styryl, A represents a member selected from the groupconsisting of (a) phenyl, (b) 4-(2-benzoxazolyl)phenyl, (c) 2-thienyl,(d) 2-thienyl substituted in position 5 with a member selected from thegroup consisting of phenyl and 2-benzoxazolyl, (e) 4-stilbenyl, (e')4-(4'- phenyl)stilbenyl, (f) B-naphthyl, (g) 4-diphenylyl, (h) w, [3-,or 'y-pyridyl and (i) 6-benzoxazoly1 substituted in position 2 with amember selected from the group consisting of phenyl, alkyl of 1 to 4carbon atoms and 2- (5-phenyl)-thienyl, wherein Q and Q are each asingle substituent in the terminal phenyl groups of A and A and arehydrogen, chlorine, alkyl containing from 1 to 6 carbon atoms and alkoxycontaining from 1 to 6 carbon atoms, B represents 1,4-phenylene andwherein m and n each is a whole number 1 or 2.

Important types of compounds of the general Formula 2 may be representedby the following general formulae in which formulae D and/or D is aphenyl, naphthyl, styryl, stilbenyl, thienyl or phenylthienyl residue,or a benzoxazolyl, benzoxazolylphenyl, oxdiazolylphenyl,benzoxazolylthienyl or oxdiazolylthienyl residue; E and/or E is aphenyl, naphthyl, styryl, stilbenyl, thienyl or phenylthienyl residue,and terminal aromatic ring systems may contain up to two substituents Ror R and each phenylene residue may contain one substituent R where R isa hydrogen or halogen atom, a linear or branched alkyl group, a phenylgroup, a halogenalkyl, hydroalkyl or cyanoalkyl group, a nitrile orhydroxyl group, an alkoxy, aralkoxy or phenoxy group, a carboxyl group,a carboxylic acid ester, amide or hydrazide group, a sulphonic acid,sulphonic acid ester or amide group, an alkylsulphone or arylsulphonegroup, or an amino group which may be substituted by acyl or1,3,5-triazinyl residues, and R represents a hydrogen or chlorine atom,an alkyl group, a free or neutralized sulphonic acid group (-SOO=cation) or a sulphonic acid amide group.

The compounds of preferred interest are those of the formula wherein Arepresents a member selected from the group consisting of (b)4-(2-oXdiazol-[4,3,4]-yl)pheny1 which is substituted in position 5 ofthe oxadiazolyl residue with phenyl, 2- thienyl, 2-(5-phenyl)thieny1 and4-stilbenyl,

(c) 2-(5-phenyl)thienyl,

(d) 4-diphenyly1,

(e) 4-stilbeny1 and wherein A represents a member selected from thegroup consisting of (b) 4-(2-benzoxazoly1)phenyl,

(c) Z-thienyl,

(d) Z-thienyl substituted in position 5 with phenyl or 2- benzoxazolyl,

(e) 4-stilbenyl,

(f) B-naphthyl,

(g) 4-diphenylyl,

( w, B- or 'v-Py y (i) 4-(2-oXdiazo1-[1,3,4] -yl)phenyl substituted inposition 5 of the oxadiazolyl with 4-diphenylyl,

(j) 2-oxdiazol-[1,3,4]- y1 substituted in position 5 with 6-(2-pheny1)-benzoxazo1y1,

(k) 6-benzoxazolyl substituted in position 2 with phenyl,

4-dipheny1yl, alkyl of 1 to 4 carbon atoms or 2-(5- phenyl) -thieny1,

and wherein Q and Q; are each a single substituent in the terminalphenyl groups in A and A and are hydrogen, chlorine, alkyl containingfrom 1 to 6 carbon atoms or alkoxy containing from 1 to 4 carbon atoms.

From the large number of possible constitutions there may be mentioned,for example, for the Formula 3 the Compounds 16 to 28, for Formula 4 theCompounds 29 to 37 and for the Formula 5 the Compounds 38 to 48:

Further groups of compounds that correspond to the structural principleof Formula 2 but do not belong to the groups represented by the Formulae3 to 5 result directly from the above examples or from theunder-mentioned manufacturing methods and are not described here indetail for the sake of brevity.

Specific types of compounds of special value may be represent by thefollowing formulae (a) Benzoxazolyl-1,3,4-oxidazole derivatives of theformula (49) u c I f e -v N N-N where U represents a diphenylyl,phenyl-oxdaizolyl, stilbenzyl or para-phenyl-stilbenyl residue and U ahydro-' gen atom or a phenyl radical. A valuable subgroup in thisformula is defined by the formula where U represents a member selectedfrom the group 7 consisting of phenyl, 4-diphenylyl, 4-stilbenyl and4-(4'- phenyl)-stilbenyl.

(b) Benzoxazolyl-1,3,4-oxdiazole derivatives of the for where V and Vrepresent identical or different phenylthienyl, stilbenyl or phenylradicals, especially a member selected from the group consisting ofphenyl and 2-(5- phenyl)-thienyl.

(c) Benzoxazolyl-1,3,4-oxdiazole derivatives of the formula where W andW represent identical or different phenyl, thienyl, phenylthienyl orstilbenyl radicals, and the terminal rings contain a substituent R; fromthe series hydrogen, alkyl containing 1 to 6 carbon atoms or alkoxycontaining 1 to 4 carbon atoms. Preferred compounds according to Formula51 are those of formula wherein E represents a member selected from thegroup consisting of phenyl, 4-stilbenyl, 2-thicnyl and 2-(5-phenyl)-thienyl, E represents a member selected from the groupconsisting of phenyl, 4-stilbenyl, 2-thienyl and 2-(5-phenyl)-thienyl,wherein Q and Q; are each a single substituent in the terminal phenylgroups in E and E and are hydrogen, chlorine, alkyl having from 1 to 6carbon atoms or alkoxy having from 1 to 4 carbon atoms.

(d) Benzoxazolyl-1,3,4-oxdiazole derivatives of the formula where Zrepresents a phenyl, diphenylyl, para'-phenyl-stilbenyl orphenyl-benzoxazolyl residue and terminal rings may contain an alkylgroup with up to 6 carbon atoms. In this formula Z especially representsa member selected from the group consisting of phenyl, 4-diphenyl,4-(4'- phenyl)-stilbenyl and 6-(2-phenyl)-benzoxazolyl and issubstituted with Q Q being hydrogen or alkyl having up to 6 carbonatoms.

(e) Benzoxazolyl-1,3,4-oxdiazole derivatives of the formula where W andW are identical or different and each represents a stilbenyl residue ora phenyl radical containing a substituent R (being hydrogen, an alkylgroup containing 1 to 6 carbon atoms or an alkoxy group containing 1 to4 carbon atoms).

(f) Benzoxazolyl-1,3,4-oxdiazole derivatives of the formula 0 o c cx(54) Q-g 131 H l 8 where X represents a Z-benzoxazolylphenyl,phenylthienyl or 2-benzoxazolyl thienyl residue which may contain alkylgroups with up to 4 carbon atoms.

(g) Benzoxazolyl-1,3,4-oxdiazole derivtives of the formula where Xrepresents a phenyl, diphenylyl, naphthyl, stilbenyl, thienyl,phenylthienyl or pyridyl residue and the terminal rings may besubstituted by alkyl groups containing l to 4 carbon atoms, by halogenatoms or alkoxy group r-4)- Of special interest within Formulas 54 and55 are compounds having the formula where E represents a member selectedfrom the group consisting of phenyl and 2-(5-phenyl)-thienyl, Erepresents a member selected from the group consisting of phenyl,4-diphenylyl, ,B-naphthyl, 4-stilbenyl, 2-thienyl, 6-benzoxazolylsubstituted in position 2 with phenyl or 2-(5-phenyl)-thienyl, andwherein Q and Q are single substituent in the terminal phenyl groups inE and E and are hydrogen, chlorine, alkyl having from 1 to 6 carbonatoms or alkoxy having from 1 to 4 carbon atoms, as Well as those offormula wherein E is 4-(Z-benzoxazolyD-phenyl, 2-(5-phenyl)- thienyl or2-[5-(2-benzoxazolyl)]-thienyl and Q is hydrogen or lower-alkyl havingfrom 1 to 6- carbon atoms.

The new benzoxazolyl-1,3,4-oxdiazole compounds are accessible by knownmethods.

For example, according to a generally applicable manufacturing methodeither a carboxylic acid halide (preferably chloride) of the Formula Iis reacted with a carboxylic acid hydrazide of the Formula II or acarboxylic acid hydrazide of the Formula III with a carboxylic acidhalide (preferably chloride) of the Formula IV to yield theacylhydrazine of the Formula V which latter is then cyclized to form thel,3,4-oxdiazole. This sequence of reactions may be showndiagrammatically as follows (A A B, m and n in these formulae having theabove meanings):

(III) (Iv) From this principal system there may be directly derivedquite analogous routes for which, for example, the following may beshown for the case of m=2and n=2 (all symbols again having the abovemeanings): l

The diacylhydrazine of the Formula X obtained in this manner is likewisecyclized. to form the 1,3,4-oxdiazole. In an identical manner, forexample, the reaction for the compound type where n: 1, the Compounds Iand VI may lac-reacted together with hydrazine. The reaction of thehalides of the Formula I, IV or VI with hydrazine or its hydrate orsalts or carboxylic acid hydrazides of the indicated formulae to yieldthe corresponding acylhydrazines may be carried out in the presence of atertiary nitrogen base at a temperature above 50 to about 150 C. Thetertiary nitrogen base to be used should not boil too low and isadvantageously one that boils at 100 C. or higher, for exampleN,N-diethylaniline or N,N-dimethylaniline. Particularly good resultshave been obtained with cyclic tertiary nitrogen bases such as quinolineand above all with pyridine bases such as pyridine itself andalkylpyridines comprising lower alkyls, such as 2-, 3- and4-methylpyridine (picolines) or ethylpyridines, or with mixture of suchpyridine bases.

Especially good results have been achieved by performing the reactionleading to the acylhydrazine of the Formula V or X in a high boiling,inert, non-polar or at most only weakly polar organic solvent, forexample, ortho-dichlorobenzene or trichlorobenzene, in the presence ofthe stoichiometrically required quantity of pyridine bases, attemperatures from 50 to 150 C., because the subsequent cyclizationleading to the 1,3,4- oxdiazole can be performed without intermediateisolationof the acylhydrazine, by dropping in somewhat more than thestoichiometrically required quantity of thionylchloride at a temperaturefrom 120 to 220 C., advantageously at the boiling temperature of thesesolvents, in a very rapid and smooth manner, that is to say that thecompounds of the Formula 1, starting from the hydraziiles, cansurprisingly be carried out by way of a singlestage process.

If desired, the compounds of the Formula 2 obtained by the processesdescribed above may be used for further reactions. Thus, water-solublederivatives are obtained when (a) the compound of the Formula 2 issulphonated, e.g. with sulphuric acid monohydrate, chlorosulphonic acidor with sulphuric acid containing sulphur trioxide, if desired at anelevated temperature, and the sulphonic acid group is then convertedwith an organic or preferably an inorganic base into the correspondingsalts;

(b) one or several primary or secondary amino groups of the compound ofthe Formula 2 is converted with sultones, e.g. with propanesultone orbutanesultone at an elevated temperature into the corresponding alkyl--sulphonic acid derivative; 7

(c) one or several primary amino groups of the compound of the Formula 2are converted with aldehydebisulphite compounds e.g. withformaldehyde-alkali metal bisulphite, into the correspondingw-methanesulphonic acid derivative;

(d) one or several primary amino groups of the compound of the Formula 2are reacted with alkylsulphonic or aralkylsulphonic acids, e.g.bromoethanesulphonic acid or benzylchloride-sulphonic acid;

(e) one or several primary or secondary amino groups or hydroxyl groupsof the compound of the Formula 2 are linked through s-triazin-Z-ylbridges'with phenolsulphonic acids or anilinesulphonic acids;

(f) in one or several hydroxyl groups er the compound of the Formula 2 apolyalkylene ether chain is introduced by means of an alkylene oxidesuch as ethylene oxide or propylene oxide or with a'polyalkylcne ethermonohalide; the said polyalkylene ether chain must be long enough toensure solubility in water;

(g) one or several groups capable of quaternation present in thecompound of the Formula 2 are reacted with quaternating agents e.g.methyliodide, dimethylsulphate, benzylchloride or toluenesulphonic acidalkyl esters at an elevated temperature, if necessary undersuperatmospheric pressure;

(h) one or several halogenoalkyl groups of the compound of the Formula 2are converted into the corresponding quaternary derivative with tertiarybases, e.g. pyridine.

The new optical brighteners of the composition defined above display inthe dissolved or finely dispersed state a more or less pronouncedfluorescence. They may be used for optically brightening a wide varietyof organic materials of high or low molecular weight or materialscontaining organic substances.

-As relevant examples the following groups of organic materials suitablefor optical brightening may be mentioned, without thereby in any wayrestricting the possible scope:

(I) Synthetic organic materials of high molecular weight:

(a) Polymers based on organic compounds containing at least onepolymerizable carbon-to-carbon double bond, i.e. their homopolymers andcopolymers and products obtained by after-treating them, such ascross-linked, grafted or decomposition products, polymer dilutions orthe like; relveant examples are: Polymers based on a, 8-unsaturatedcarboxylic acids, especially of acryl compounds (e.g. acrylic esters,acrylic acids, acrylonitrile, acrylamides and their derivatives or their'methacrylic analogues), of olefinic hydrocarbons (e.g. ethylene,propylene, isobutylene, styrenes, dienes, especially butadiene, isoprenei.e. also rubbers and rubber-like polymers; furthermore socalled ABSpolymers), polymers based on vinyl and vinylidene compounds (e.g. vinylesters, vinylchloride, vinylsulphonic acid, vinyl ethers, vinyl alcohol,vinylidenechloride, vinylcarbazole); of halogenated hydrocarbons(chloroprene, highly halogenated ethylenes), of unsaturated aldehydesand ketones (e.g. acrolein or the like), of allyl compounds or the like;graft polymerization products (e.g. by grafting vinylic monomers),crosslinked products, e.g. by means of bifunctional or polyfunctionalcross-linking agents such as divinylbenzene, polyfunctional allylcompounds or bisacryl compounds, or products accessible by partialdecomposition (hydrolysis, depolymerization) or modification of reactivegroupings (e.g. esterification, etherification, halogenation,auto-crosslinking).

(b) Other polymers accessible, for example, by ring opening e.g.polyamides of the polycaprolactam type; furthermore formaldehydepolymers or polymers accessible by polyaddition as well as bypolycondensation, such as polyethers, polythioethers, polyacetals andthioplasts;

(c) polycondensation products or precondensates based on bifunctional orpolyfunctional compounds containing condensable groups, their homoandco-condensates and products obtained by after-treating them; relevantexamples are:

Polyesters, saturated (e.g. polyethylene terephthalate) or unsaturated(e.g. maleic acid-dialcohol polycondensates and their cross-linkedproducts with polymerizable vinyl monomers), linear or branched (alsothose based on polyhydric alcohols e.g. alkyd resins). Polyamides (e.g.hexamethylenediamine adipate), maleinate resins, melamine resins,phenolic resins (novolaks), aniline resins, furan resins, carbamideresins and their precondensates, and similarly constituted products,polycarbonates, silicone resins and others.

(d) Polyadducts such as polyurethanes (if desired cross-linked), epoxyresins.

(II) Semisynthetic organic materials e.g. cellulose esters or mixedesters (acetate, propionate, nitrocellulose, cellulose ethers,regenerated cellulose [viscose, cuprammonium cellulosel) or productsobtained by aftertreating them; casein plastics.

(III) Natural organic materials of animal or vegetable origin, e.g.based on cellulose or proteins such as wool, cotton, silk, bast, jute,hemp, furs and hairs, leathers, finely dispersed wood masses, naturalresins (such as colophony, especially lacquer resins); furthermorerubber, gutta percha, balata and products obtained by after-treating ormodifying them (e.g. by curing, crosslinking), decomposition products(e.g. by hydrolysis, depolymerization, grafting); products accessible byconversion of reactive groups (e.g. by acylation, halogenation,cross-linking or the like).

The organic materials that can be optically brightened may be at anystage of their processing (raw materials, semi-finished products orfinished articles) and physical states. They may be in the form ofstructures of any desired shape, that is to say, for example, they maybe predominantly three-dimensional bodies such as blocks, plates,sections, pipes, injection mouldings or components of any desired kind,chips or granulates, foamed articles; predominantly two-dimensionalbodies such as films, foils, lacquers, tapes, coatings or impregnations;or predominantly unidirnensional bodies such as filaments, fibres,flocks, bristles or wires. The said materials may also be as yet notshaped and be in the most varied homogeneous and inhomogeneous forms ofdispersion and physical states, for example in the form of powders,solutions, emulsions, dispersions, latices (e.g. lacquer solutions,polymer dispersions), sols, gels, putties, pastes, waxes, adhesives,pore fillers or the like.

Fibrous materials may, for example, take the form of continuousfilaments, staple fibres, flocks, hanks, textile threads, yarns, doubledyarns, fibre fleeces, felts, cottonwool, flocculated products or oftextile fabrics or textile laminates, knitwear, of papers, cardboards,paper pulps or the like.

The compounds to be used according to this invention are of specialvalue for the treatment of textile organic materials, especially woventextile fabrics. If fibres-which may be stable fibres or continuousfilaments, in the form of hanks, woven or knitted fabrics, fleeces,flocculated substrates or laminatesare to be optically brightened by thepresent process, this is advantageously done in an aqueous medium inwhich the chosen compound is finely dispersed (suspended or, if desired,dissolved). If desired, there may be added to the treatment liquor adispersant, for example soaps, polyglycol ethers of fatty alcohols,fatty amines or alkylphenols, cellulose sulphite waste liquor orcondensation products of (possibly alkylated) naphthalenesulphonic acidswith formaldehyde. It has been found particularly advantageous to workin a neutral, weakly alkaline or acid bath. Likewise, it is advantageousto perform the treatment at a temperature from about 50 to 100 C., forexample at the boiling temperature of the bath or in its vicinity (atabout 90 (3.). The improving treat- 12 ment according to this inventionmay also be carried out with solutions in organic solvents.

Furthermore, the new optical brighteners to be used in this inventionmay be added to, or incorporated with, the materials before or duringtheir shaping. Thus, for example, in the manufacture of films, foils,tapes or mouldings they may be added to the moulding or injectionmoulding composition or they may be dissolved, dispersed or in any otherway finely distributed in the spinning mass before spinning. The opticalbrighteners may also be added to the starting materials, reactionmixtures or intermediate products used to produce fully synthetic orsemi-synthetic organic materials, that is to say before or during thechemical reaction, e.g. a polycondensation (including theprecondensates), a polymerization (including the prepolymer) or apolyaddition.

The new optical brighteners can, of course, also be used wheneverorganic materials of the kind indicated above are combined withinorganic materials in any desired form (typical examples: detergents,white pigments in organic substances).

The new optical brighteners are distinguished by their particularly goodheat resistance and fastness to light and to migration.

The amount of the new optical brightener to be used according to thisinvention, referred to the weight of the material to be opticallybrightened, my vary within wide limits. Even very small amounts, in somecases for instance as little as 0.001% by weight, may suflice to producea distinct and durable eflect, though it is also possible to use amountsof up to about 0.5% by weight or more. For most practical purposes anamount ranging from 0.01 to 0.2% by weight will be preferred.

The new compounds, to be used as brightening agents, may also beapplied, for example, as follows:

(a) In admixture with dyestuffs or pigments or as additives to dyebaths,or printing, discharge or reserve pastes. Also for after-treatingdyeings, prints or dis charge prints.

(b) In admixture with so-called carriers, antioxidants,

light filters, heat stabilizers, chemical bleaches or as additives tobleaching baths.

(c) In admixture with cross-linking agents, dressings such as starch orsynthetic dressings. It may also be of advantage to add the products ofthis invention to the liquors used for producing an anti-crease finish.

(d) In combination with detergents, the detergent and the opticalbrightener may be added separately to the washing liquor. It is alsoadvantageous to use detergents that as such already contain a share ofbrightening agent. Suitable detergents are e.g. soaps, salts orsulphonate washing agents e.g. of sulphonated benzim idazolessubstituted on the carbon atom 2 by higher alkyl radicals, also salts ofmonocar boxylic acid esters of 4-sulphophthalic acid with higher fattyalcohols, also salts of fatty alcohol sul-phonates, alkylarylsulphonicacids or condensation products of higher fatty acids with aliphatichydroxysulphonic or aminosulphonic acids. Furthermore, there may be usednon-ionic detergents e.g. polyglycol ethers derived from ethylene oxideand higher fatty alcohols, alklyphenols or fatty amines.

(e) In combination with polymeric vehicles (polymers,

polycondensates or polyadducts) in which the brightening agent, ifdesired in addition to other substances, is incorporated in thedissolved or dispersed form, for example in the case of coating,impregnating or binding agents (solutions, dispersions, emulsions) fortextile materials, fleeces, papers or leathers.

(f) As additives to a wide variety of industrial products to improvetheir presentation or to obviate disadvantages in their use, for exampleas additives to glues, adhesives, paints or the like.

The compounds of the above formulae can be used asscintillators,for'various photographic purposes, such aselectrophotographic reproduction or for supersensitizing.

If the brightening operation is to be combined with other treating orimproving operations, the combined treatment is advantageously performedwith the use of a suitable stable preparation which contains in additionto optically brightening compounds of the above general formula alsodispersants, detergents, carriers, dyestuffs, pigments or dressingagents.

The treatment of the polyester fibres with the brighteners of thisinvention may-also consist, forjexample, in impregnating these fibreswith an aqueous dispersion of the brightener at a temperature below 75C., for example at room temperature, and then subjecting them to a dryheat treatment at a temperature above 100 C.; in this connection it isin general advantageous first to dry the fibrous material at amoderately raised temperature, for example within the range from atleast 60 C. to at most about 100 C. The heat treatment of the drymaterial is then advantageously carried out at a temperature between 120and 225 C., for example by heating it in a drying chamber, by ironing itwithin the indicated temperature range or by treating it with dry,superheated steam. The drying and the dry-heat treatment may also beperformed one immediately following upon the other or they may becombined in a single operational step.

In the following Tables Column I=formula number, Column II=structuralformula, Column III=melting point in C. (uncorrected), Column IV:empirical formula and analytical data (upper line: calculated, lowerline: found), Column V=recrystallizing medium which itself is referredto by the following symbols: l=dimethylformamide 2=ortho-dichlorobenzene3 =trichlo'rob enzene 4= ortho-dichlorobenzene/tetrachloroethylene5=tetrachloroethylene 6=chlorobenzene EXAMPLE 1 A mixture of 8.0 g. ofthe dicarboxylic acid dichloride of the formula 9.6 g; of para-tertiarybutylbenzoic acid hydrazide and 8 g. of pyridine in 200 ml. of anhydrousorthodichlorobenzene is heated within 20 minutes to 100 to 110 C. whilebeing stirred, then further stirred for 1 hour at this temperature andthen within 15 to 30 minutes heated to 165 to 170 C. Within 15 minutesat 165 to 170 C. 12 g. of thionylchloride are vigorously stirred intothe almost colourless suspension. The yellow, almost completelydissolved reaction product, is further stirred for minutes at thistemperature, cooled to about 20 C. 100 ml; of methanol are added, andthe precipitated 1,3,4- oxdiazole derivative of the formula j issuctioned off, washed with methanol and dried, to yield about 7.3 g.=49.0% of theory) of an almost colourless powder melting at 301.5 to302.5 C. which, after three recrystallizations from dimethylformamidewith the aid of active carbon, forms pale-yellowish, very fine needlesmelting at 3l0.5 to 311 C.

Analysis.-C H O N (molecular weight: 595.67). Calculated (percent): C,74.60; H, 5.58; N, 11.76. Found (percent): C, 74.57; H, 5.56; N, 11.77.

i it

The dicarboxylic acid dichloride of the Formula 56 used as startingmaterial can be prepared as follows:

A mixture of 132.5 g. of terephthalic acid monomethyl ester chloride,112 g. of 4-amino-3-hydroxybenzoic acid methyl ester and /2 litre ofanhydrous ortho-dichlorobenzone is stirred, thenlslowly heated to thereflux temperature, during which at to C. a strong evolution of hydrogenchloride gas sets in. The batch is refluxed for 2 hours whereby a darksolution is obtained; 1 g. of boric acid anhydride is added and thetemperature of the reaction mixture is slowly raised to 210 to 215 C.,whereby part of the solvent is caused to pass over as an azeotrope withthe water of reaction.

The batch is stirred for one hour at this temperature and then allowedto cool. The solidified melt is dissolved in about 4 litres of hotdioxane. The solution is decolorized with 20 g. of active carbon andallowed to crystallize, to yield about 183 g. (=88% of theory) of thecompound of the formula in the form of colourless needles melting at 219to to 220 C.

Analysis.C H O N (molecular Weight: 311.28). Calculated (percent): C,65.69; H, 4.21; N, 4.50. Found (percent): C, 65.33; H, 4.19; N, 4.40.

87 grams of the dicarboxylic acid ester of the Formula 58 in 1.3 litresof ethyleneglycol monomethyl ether are heated to refluxing. Within 10minutes a solution of 50 g. of sodium hydroxide in 150 ml. of water isthen run in. At first, a clear solution is obtained from which thedisodium salt immediately settles out as a light-yellow, crystallineprecipitate. The batch is refluxed for another 20 minutes, whereupon aspecimen of the reaction mixture gives a clear solution in water. Thewhole is suctionfiltered at room temperature and the filter residue isrinsed with methanol and then dissolved in 3 liters of hot water. Thissolution is decolorized with active carbon and then rendered acid toCongo red with dilute hydrochloric acid. The resulting, voluminousprecipitate is suctioned off at room temperature and washed neutral withwater. After drying, there are obtained about 68 g. (=86% of theory) ofthe compound of the formula as a colorless powder melting above 350 C.

66.4 grams of the above dicarboxylic acid of the Formula 59 aresuspended in 1.2 liters of chlorobenzene. 100 ml. of thionylchloride and5 ml. of dimethylformamide are added, and the whole is stirred for 16hours at 90 to 95 C., during which hydrochloric acid gas escapes and aclear solution forms. The bulk of the solvent is suctioned off undervacuum and the residue is mixed with hexane. On filtering with suction,washing the residue with hexane and drying, there are obtained about68.5 g. (=91% of theory) of the dicarboxylic acid dichloride of theFormula 56 as colorless, fine needles melting from 158 C. to 160 C.

The 1,3,4-oxdiazole derivatives listed in the following 75 Table A areaccessible in a similar way:

1 II III IV v 76 222.5-223 og H uo N s 8O N931 9.

f CH 68.95, H 3.99, N 9.17

O Q- M OCH;

0 OH 4 4 R Q 0 00m s in the form of a light-beige powder which melts anddecomposes at 267 C. and after two recrystallizations from dioxane formsbundles of pale-yellow needles which melt and decompose at 268 C.

Analysis.'C H O N (molecular weight: 353.33). Calculated (percent): C,64.58; H, 4.28; N, 3.96. Found (percent): C, 64.82; H, 4.36; N, 3.83.

A mixture of 46.0 g. of the amide of the Formula 77 and 70 ml. ofdibutylphthalate is heated with stirring and exclusion of air to 310 C.and then stirred on for 5 minutes at 310 to 315 C., allowed to cool,during the cooling 100 ml. of methanol are added, and the whole isfinally cooled to room temperature. The precipitate formed is suctionedoif, washed with methanol and dried, to yield about 40. 0 g. (=91.7% oftheory) of the ester of the formula OCH;

which melts at 200 to 201 C. and, after recrystallization from dioxanewith the aid of active carbon, forms light-yellow crystals which afterdistillation under a high vacuum melt at 203.5 to 204 C.

Analysis.-C H O NS (molecular weight: 335.38). Calculated (percent): C,68.04; H, 3.91; N, 4.18. Found (percent): C, 68.24; H, 3.87; N, 4.17.

26.3 grams of the ester of the Formula 78 are dissolved in 900 ml. ofabsolute ethanol and hydrolyzed by being refluxed for 4 hours with asolution of 16 g. of sodium hydroxide in m1. of water. The batch iscooled to about C., suctioned and the filter cake is washed withmethanol, then acidified in 1.5 litres of water at 80 C. with 50 m1. ofconcentrated hydrochloric acid while being stirred, stirred on for 15minutes, suctioned and the filter residue is washed neutral with waterHaC-C- and dried, to yield about 25.3 g. (=100% of theory) of thecarboxylic acid of the formula HOOH Q M which after tworecrystallizations from dimethylformamide melts at 287 to 288 C.

Analysis.-C H O NS (molecular weight: 321.35). Calculated (percent): C,67.28; H, 3.45; N, 4.36. Found (percent): C, 66.80; H, 3.57; N, 4.58.

22.3 grams of the carboxylic acid of the Formula 79 are stirred in 750ml. of chlorobenzene; ml. of thionylchloride and 2 ml. ofdimethylformamide are added and the batch is allowed to react for 2hours at 120 C. After this period another 75 ml. of thionylchloride and2 ml. of dimethylformamide are added and the whole is stirred foranother 2 hours at 120 C. The excess thionylchloride together with abouthalf the solvent is distilled off, the distillation residue is filteredwhile still hot and then allowed to cool. The carboxylic acid chlorideof the Formula 63 forms small, yellow crystalline needles which aftersuctioning, washing with n-hexane and drying melt at 196 to 198 C.Yield: about 20 g. (=83.5% of theory). After two recrystallizations fromchlorobenzene the melting point rises to 199 to 200 C.

Analysis.-C H O NSCl (molecular weight: 339.80). Calculated (percent):C, 63.63; H, 2.97; N, 4.12; Cl, 10.43. Found (percent): C, 63.58; H,2.99; N, 4.01; Cl, 10.47.

EXAMPLE 3 A mixture of 3.13 g. of the carboxylic acid chloride of theformula 2.53 g. of 4-[benzoxazolyl (2')] benzoic acid hydrazide of theformula and 1.6 g. of pyridine in ml. of anhydrous ortho-dichlorobenzeneis heated within 25 minutes to 100 to C. while being stirred, thenfurther stirred for 1 hour at this temperature and then within 20minutes heated to to C. In the course of 30 minutes at 130 to 135 C. 2.5m1. of thionylchloride are dropped into the pale-yellow reactionproduct. The batch is stirred for another 30 minutes at 130 to 135 C.,then cooled to about 5 C. and during the cooling 200 ml. of methanol areadded. The 1,3,4-oxdiazole of the formula is suctioned 01f, washed withmethanol and dried, to yield as a white, crystalline powder which meltsat 123 to 125 about 4.4 g. (=85.9% of theory) of a light-beige, finelyC. and furnishes from methanol+methylenechloride crystalline powderwhich melts at 336 to 337 C. and white, small needles melting at 129 to130 C.

after three recrystallizations from ortho-dichlorobenzene Analysis.C H ON (molecular weight: 309.35). with the aid of bleaching earth furnishesabout 30 g. Calculated (percent): C, 73.76; H, 6.19; N, 4.53%. (=58.5%of theory) of colourless, fine, felted needles 5 Found (percent): C,73.56; H, 6.01; N, 4.71%.

melting at 338 to 339 C. A solution of 50 parts of sodium hydroxidepellets in Analysis.C H O N (molecular weight 512.54). 100 parts byvolume of water is diluted with 2000 parts by Calculated (percent): C,74.98; H, 4.72; N, 10.93. Found volume of alcohol and refluxed. 263parts of carboxylic (percent): 1 C, 74.46; H, 4.76; N, 10.73. acid esterof the Formula 86 are slowly stirred in. The

The following 1,3,4-oxdiazole derivatives are accessible 1O reactionmixture is further worked up as described in in a similar way: Example 2for the compound of the Formula 77, to yield in a yield of 88.0% of thetheoretical, in almost colourabout 220 Parts of theory) of the Compoundof less, very fine crystals from tetrachloroethylene, melting at theformula 270 to 270.5 c. (87) Analysis.-C H O N S (molecular Weight:477.59). 1 Calculated (percent): C, 72.93; H, 4.85; N, 8.80. Found(ljfla COOH (percent): C, 72.83; H, 4.80; N, 8.74. 0

O HC-CH Y 0 HBJ; \N N 41113 in a yield of 88.7% of the theoretical, as afaintly greenish as a colourless powder which melts at 247 to 253 C.,and yellow, finely crystalline powder from tetrachloroethylene, from.chlorobeglzene flgrmshes colourless: fine crystals melting at to 324 Cmelting at 259 to 262 C.

' 40 Analysis.-C H O N (molecular weight: 295.33).

s4 so 3 4 (molecular Weight: Calculated (percent): 0, 73.20; H, 5.80; N,4.74. Found Calculated (percent): C, 71.06; H, 5.26; N, 9.75. Found 2t); C, 73.23; H, 5.76; N, 4.69.

(percent): C, 70.23; H, 5.29; N, 9.67. 215 parts of the above carboxylicacid of the Formula mo-h-Qo U, ll 1} in a yield of 89.3% of thetheoretical, in colourless, very 87 are suspended in 2000 parts byvolume of chlorofine needles from ortho-dichlorobenzene, melting at 351benzene, 300 parts by volume of thionylchloride and 6 to 352 C. parts byvolume of dimethylforrnamide are then added as Analysis.C H- O N(molecular weight: 615.69). described in Example 2 for the compound ofthe Formula Calculated (percent): C, 76.08; H, 4.75; N, 11.37. Found 63,and the reaction mixture is further processed in the (percent): C,75.89; H, 4.86; N, 11.34. same way, to yield about 206 parts (=90% oftheory) of The carboxylic acid chloride of the, Formula 80 used thecarboxylic acid chloride of the formula as starting material isaccessible by the following route:

A mixture of 197 parts of para-tertiary butylbenzoic acid chloride, 167parts of 4 amino-3-hydroxybenzoic (30) N acid methyl ester, 1 part byvolume of pyridine and 1000 (3H3 parts by volume ofortho-dichlorobenzene is stirred under 11,0-0- 0 2 nitrogen. Thereaction mixture is then further worked (3H3 0 up as described inExample 2 for the compound of the 0 Formula 78, to yield about 277 parts(=90% of theory) of the compound of the formula (35) CH in the form ofpale-yellow, fine needles which melt at 3 132 to 133 C. and from hexanefurnishes colourless,

fine needles melting at 135 to 136 C.

C 000cm Analysis.-C H NO Cl (molecular weight: 313.77

Calculated (percent): C, 68.90; H, 5.14; N, 4.46; Cl,

Still contains a trace of ortllo-dichlorobenzene. Found (Percent) 4'44;2 Still contains traces of tetrachloroethylene.

23 24 EXAMPLE 4 EXAMPLE 5 A mixture of 6.58 g. of the carboxylic acidhydrazide A mixture of 3.55 g, of the carboxylic acid hydrazide of theformula of the formula 0 r (94) O as o 0 -o o CH=CH- o NH NH NII-NH a2.17 g. of diphenyl-4-carboxylic acid chloride and 1.6 g. of pyridine in100 ml. of anhydrous ortho-dichloro- 2.81 g. of benzoylchloride and 3.2g. of pyridine in 200 benzene is reacted with 2.5 ml. of thionylchlorideas deml. of anhydrous ortho-dichlorobenzene is reacted with scribed inExample 3, to yield about 3.0 g. (=58.0% of 5 ml. of thionylchloride asdescribed in Example 3, to theory) of the 1,3,4-oxidazole derivative ofthe formula yield about 6.0 g. (=72.2% of theory) of the 1,3,4-oxdiazole derivative of the formula On recrystallization fromdibutylphthalate+methanol and then from ortho-dichlorobenzenepale-yellow, fine needles melting at 317 to 317.5 C. are obtained.

0 O Analysis.C H O N (molecular weight: 517.59).

Calculated (percent): C, 81.22; H, 4.48; N, 8.12. Found (percent): C,81.10; H, 4.39; H, 8.11.

pared 1n a srmllar manner, the crude product 111 each case beingrecrystallized once from dibutylphthal- The folowing 1,3,4-oxdiazo1ederivatives may be prewhich is recrystallized fromdibutylphthalate+methanol ate+methanolz and then fromortho-dichlorobenzene to form colourless, in a yield of 26.5% oftheoretical, in faintly greenish shiny flakes melting at 241.5 to 242 C.yellow, fine needles from tetrachloroethylene, melting at Analysis.-C HO N (molecular weight: 415.45 250 to 260.5 c.

Calculated (percent): C, 78.06; H, 4.12; N, 10.11. Found Analysis.C H ON (molecular weight: 441.47).

(percent): C, 77.90; H, 4.30; N, 10.32. Calculated (percent): C, 78.89;H, 4.34; N, 9.52. Found The 1,3,4-oxdiazole derivatives listed in thefollowing (percent): C, 78.69; H, 4.44; N, 9.59. Table C may be preparedin a similar manner, the crude product in each case being recrystallizedonce from dibutylphthalate+methanol I 11 III IV v 90---.- o 0 250-250. 5C2sH19O2Na1 2 0 78.31, H 4.45, N 9.79 @G C 3 orra 0 78.58, H 4.51, N9.95

281382 i J sii i fir 4 31 N s 2 2 92 O O 325326 C4lH2702N3I 0 52.95, H4.53, N 7.08 -g -c1-1=c1rc 82.70, H 4 31, N 7.12

93.... 0 O 0 297-299 CgsHtsOaNa 6 on. c 77.53, H 4 79, N 9.52 o 77 50, H5 03, N 9.51 1 1U cc o1r,

CH N N EXAMPLE 6 A mixture of 17.0 g. of the carboxylic acid chloride ofthe Formula 63, 1.25 g. of hydrazine hydrate and 8 g. of pyridine in 200ml. of anhydrous ortho-dichlorobenzene is heated within 20 minutes to100 to 110 C., while being stirred, then stirred on for 1 hour at thistemperature and then within to 30 minutes heated to 165 to 170 C. In thecourse of 15 minutes at 165 to 170 C. 12 g. of thionylch-loride aredropped into the vigorously stirred, faintly yellowish suspension of thereaction product. The yellow suspension is stirred for another 5 minutesat this temperature, then cooled to about C., and the precipitated1,3,4-oxidazole derivative of the formula is suctioned 01f, washed withmethanol, and dried, to yield about 13.4 g. (=86.4% of theory) of ayellow, crystalline in a yield of 68.5% of the theoretical, in almostcolourless, fine crystals from tetrachloroethylene, melting at 311 to312 C.

Analysis.C H O N-% C C1 (molecular weight: 585.23). Calculated(percent): C, 74.29; H, 5.50; N, 9.58; CI, 2.42. Found (percent): C,74.18; H, 5.61; N, 9.54; CI, 1.89.

in a yield of 29.9% of the theoretical, in colourless, very 7Q fineneedles from ortho-dichlorobenzene, melting at 373 to 374 C. V

Analysis.C H O' N (molecular weight: 636.68). Calculated (percent): C,71.68; H, 5.07; N, 13.20. Found (percent) C, 70.98; N, 4.88; N, 12.89.

EXAMPLE 7 A polyester fabric (for example Dacron) is padded at roomtemperature (about 20 C.) with an aqueous dispersion containing, perlitre, 2 g. of the compound of the Formula 36-and 1 g. of an adduct fromabout 8 mols of ethylene oxide with 1 mol of para-tertiary octylphenol,and then dried at about 100 C. The dry material is then developed by aheat treatment for 30 seconds at 220 C. The material treated in thismanner has a substantially whiter aspect than the untreated fabric.

EXAMPLE 8 100 grams of a polyester granulate from terephthalic acidethyleneglycol polyester are intimately mixed with 0.01 g. of thecompound of the Formula 16 and melted at 285 C. while being stirred. Thespinning mass is spun through conventional spinnerets and stretched tofurnish strongly brightened polyester fibres.

Alternatively, the compound of the Formula 16 may be added to thestarting material before or during the polycondensation leading to thepolyester.

Good brightening elfects are also obtained when the compound of theFormula 16 is replaced by the compound of the Formula 37, 62, 67, 92, or96.

EXAMPLE 9 10,000 parts of a polyamide in chip form, prepared in theknown manner from e-caprolactam, are mixed for 12 hours in a tumblerwith 30 parts of titanium dioxide (rutile modification) and 5 parts ofthe compound of the Formula 16, 60, 65, 67, 92 or 96. The chips treatedin this manner are then melted in a boiler from which the atmosphericoxygen has been displaced and which is heated at 270 C., and the melt isstirred for half an hour. The melt is then expressed through a spinneretunder a nitrogen pressure of 5 atmospheres (gauge) and the cooledfilament is wound up on a spinning bobbin. The filaments thus obtaineddisplay a good brightening effect.

Similar brightening efiects can be achieved on a polyamide fromhexamethylenediamine adipate.

What is claimed is:

1. A benzoxazolyl-l,3,4-oxadiazole derivative of the formula C A) 4.4% L

wherein A represents a member'selected from the group consisting of a 19 I (a) phenyl, v v i (b) 4-(2 oxdiazol-[l,3,4]yl)phenyl whichisssubstituted in'position 5 'of the oxdia'zolyl residue with phenyl,Z-thienyl; 2=(5-phenyl)thien-yl or 4-stilbenyl, (c) 2-(5-phenyl)thienyl,(d) 4-diphenylyl,' (e) 4-stilbenyl, and y y A represents a memberselected from the group consisting of (b) 4-(2-benzoxazolyl)phenyl,

(c) Z-thienyl,

(d) Z-thienyl substituted in position 5 with phenyl or Z-benzoxazolyl,

(e) 4-stilbenyl,

( e) 4- (4'-phenyl stilbenyl,

(f) B-naphthyl,

(g) 4-diphenylyl,

( w, B- or v-py y (i) when n is 1, 4-(2-oxidiazol-[1,3,4]-yl)phenylsubstituted in position 5 of the oxadiazolyl with 4-diphenylyl,

(j) 2-oxdiazol-[l,3,4]-yl substituted in position 5 with 6- Z-phenylbenzoxazolyl,

(k) 6-benzoxazolyl1 substituted in position 2 with phenyl, 4-diphenylyl,ialkyl of 1 to 4 carbon atoms or 2- S-phenyl -thienyl,

and wherein Q and Q represents up to two substituents in the terminalphenyl groups in A and A and are hydrogen, chlorine, alkyl containingfrom 1 to 6 carbon atoms or alkoxy containing from 1 to 6 carbon atoms,B represents an unsubstituted 1,4-phenylene and wherein m and it each isa whole number 1 or 2.

2. The compound of claim 1, wherein m and n are 1.

3. A benzoxazolyl-1,3,4-0xadiazole derivative of the formula c c E @flfifi*@ 13 H 2 Q5 N N-N Q6 wherein E represents a member selected from thegroup consisting of phenyl, 4-stilbenyl, 2-thienyl and 2-(5-henyD-thienyl, E represents a member selected from the group consistingof phenyl, 4-stilbenyl, Z-thienyl and 2-(5-phenyl)-thienyl, wherein Qand Q; are each a single substituent in the terminal phenyl groups in Eand E and are hydrogen, chlorine, alkyl having from 1 to 6 carbon atomsor alkoxy having from 1 to 4 carbon atoms.

4. A benzoxazolyl-l,3,4-oxadiazole derivative having the formula where Zrepresents a member selected from the group consisting of phenyl,4-diphenylyl, 4-(4-phenyl)-stilbenyl and 6-(2-phenyl)-benzoxazoly1,wherein Q is a substituent in the terminal phenyl group of group Z andis hydrogen or alkyl having up to 6 carbon atoms.

5. A benzoxazolyl-1,3,4-oxadiazole derivative having the formula where Urepresents a member selected from the group 28 consisting of phenyl,4-diphenyly1; 4-stilbenyl and 4-(4'- phenyl)stilbenyl.

6. A benzoxazolyl-l,3,4-oxadiazole derivative having the formula o C/ Vn1! n 2 N N 'N N where V and V represents a member selected from thegroup consisting of phenyl and 2-(5-phenyl)-thienyl.

7. A benzoxazolyl-1,3,4-oxadiazole derivative having the formula 10 N NNwherein E is 4-(Z-benzoxazolyD-phenyl, 2-(5-phenyl)- thienyl or2-[5-(2-benzoxazolyl)]-thieny1 and Q is hy drogen or lower-alkyl havingfrom 1 to 6 carbon atoms.

9. The compound according to claim 1 having the formula 0 o @H/ m 10.The compound according to claim 1 having the formula 11. The compoundaccording to claim 1 having the formula 12. The compound according toclaim 1 having the formula NN 13. The compound according to claim 1having the formula O c c Q-cmcn n u N HN (References on following page)30 us. 01. X.R.

29 References Cited UNITED STATES PATENTS 3,328,310 6/ 1967 Maeder eta1. 260-307 HENRY R. JILES, Primary Examiner H. I. MOATZ, AssistantExaminer

